1. Field of the Invention
Embodiments of the present invention relate generally to methods of making tubing connections and more particularly to methods of making connections between hydraulic control lines such as those used in downhole applications.
2. Description of the Related Art
The following descriptions and examples are not admitted to be prior art by virtue of their inclusion in this section.
Hydraulic fluid is widely used to communicate with and/or actuate various downhole tools and components. One means of conveying the hydraulic fluid to the tools and components is through the use of various diameters (¼″, ½″ etc) of hydraulic control lines selected according to the particular application. The control lines are typically seamless or seam-welded continuous metal tubes with various wall thicknesses (0.035″, 0.049″, etc). Since a control line may provide communication and hydraulic power between various tools or between the wellhead and the tools, some control lines can be pressure rated for up to 25 Ksi or more. When a control line is used in a downhole application, reliability is critical (i.e., no fluid leaks along the length of a control line). One area of concern in terms of reliability is with the termination to downhole tools and wellheads as well as with the individual splice connections (when present). Tool terminations and splices are traditionally done using hydraulic fittings that rely on metal-to-metal seals. However, this involves an increased risk due at least in part to the introduction of two potential leak paths via the two metal-to-metal primary seals per splice connection, along with the associated cost of storage of an inventory of couplings that must be made to relatively strict tolerances.